bresenham3d.py

# Python3 code for generating points on a 3-D and 2-D line
# using Bresenham's Algorithm
# from https://www.geeksforgeeks.org/bresenhams-algorithm-for-3-d-line-drawing/
# and https://www.geeksforgeeks.org/chain-code-for-2d-line/

def Bresenham3D(x1, y1, z1, x2, y2, z2):
    ListOfPoints = []
    ListOfPoints.append((x1, y1, z1))
    dx = abs(x2 - x1)
    dy = abs(y2 - y1)
    dz = abs(z2 - z1)
    if (x2 > x1):
        xs = 1
    else:
        xs = -1
    if (y2 > y1):
        ys = 1
    else:
        ys = -1
    if (z2 > z1):
        zs = 1
    else:
        zs = -1

    # Driving axis is X-axis"
    if (dx >= dy and dx >= dz):
        p1 = 2 * dy - dx
        p2 = 2 * dz - dx
        while (x1 != x2):
            x1 += xs
            if (p1 >= 0):
                y1 += ys
                p1 -= 2 * dx
            if (p2 >= 0):
                z1 += zs
                p2 -= 2 * dx
            p1 += 2 * dy
            p2 += 2 * dz
            ListOfPoints.append((x1, y1, z1))

    # Driving axis is Y-axis"
    elif (dy >= dx and dy >= dz):
        p1 = 2 * dx - dy
        p2 = 2 * dz - dy
        while (y1 != y2):
            y1 += ys
            if (p1 >= 0):
                x1 += xs
                p1 -= 2 * dy
            if (p2 >= 0):
                z1 += zs
                p2 -= 2 * dy
            p1 += 2 * dx
            p2 += 2 * dz
            ListOfPoints.append((x1, y1, z1))

    # Driving axis is Z-axis"
    else:
        p1 = 2 * dy - dz
        p2 = 2 * dx - dz
        while (z1 != z2):
            z1 += zs
            if (p1 >= 0):
                y1 += ys
                p1 -= 2 * dz
            if (p2 >= 0):
                x1 += xs
                p2 -= 2 * dz
            p1 += 2 * dy
            p2 += 2 * dx
            ListOfPoints.append((x1, y1, z1))
    return ListOfPoints


def Bresenham2D(x1, y1, x2, y2):
    ListOfPoints = []
    ListOfPoints.append((x1, y1))
    xdif = x2 - x1
    ydif = y2 - y1
    dx = abs(xdif)
    dy = abs(ydif)
    if(xdif > 0):
        xs = 1
    else:
        xs = -1
    if (ydif > 0):
        ys = 1
    else:
        ys = -1
    if (dx > dy):

        # Driving axis is the X-axis
        p = 2 * dy - dx
        while (x1 != x2):
            x1 += xs
            if (p >= 0):
                y1 += ys
                p -= 2 * dx
            p += 2 * dy
            ListOfPoints.append((x1, y1))
    else:

        # Driving axis is the Y-axis
        p = 2 * dx-dy
        while(y1 != y2):
            y1 += ys
            if (p >= 0):
                x1 += xs
                p -= 2 * dy
            p += 2 * dx
            ListOfPoints.append((x1, y1))
    return ListOfPoints


def main():
    (x1, y1, z1) = (-1, 1, 1)
    (x2, y2, z2) = (5, 3, -1)
    ListOfPoints = Bresenham3D(x1, y1, z1, x2, y2, z2)
    ListOfPoints2D = Bresenham2D(x1, y1, x2, y2)
    print(ListOfPoints)
    print(ListOfPoints2D)


if __name__ == '__main__':
    main()